SCBA's are commonly used among personnel such as firefighters to protect them from exposure to harmful atmospheres and other dangers. A typical SCBA usually includes at minimum a cylinder of compressed breathing air and a face mask, with an air hose running therebetween. The face mask component of a SCBA commonly includes adjustable webbing or straps that are configured to be worn about the head in such a way as to create a tight seal between the face mask and the wearer's face. In many SCBA systems, positive air pressure is maintained within the area between the wearer's face and the face shield to help keep harmful atmospheric elements from being inhaled.
While an SCBA can protect firefighters' lungs from so-called ‘immediately dangerous to life and health’ (IDLH) atmospheres, the unpredictability of fire growth and spread remains one of the most perilous factors in the profession. The contents of common household and business dwellings are being manufactured with increasing amounts of petroleum products, which leads to the evolution of dark, black smoke, especially during the growth stage of a fire. Rapid fire growth coupled with the production of dense smoke can result in a complete loss of visibility within a structure in a very short time.
Even the most experienced firefighters can succumb to disorientation within reduced-visibility environment, sometimes with perilous outcomes. For example, a firefighting crew may need to evacuate quickly along a planned evacuation route due to changing circumstances, rapidly-evolving fire, or an imminent flashover. In these cases, maintaining orientation to features of the structure (entrance doors, windows, etc.) can be critical. Likewise, SCBA cylinders carry a fixed volume of air, typically enough to work in an IDLH atmosphere for 30-45 minutes, so firefighters are trained to monitor their air reserves and retreat when necessary. Disorientation can result in a firefighter remaining in an IDLH atmosphere for a time period beyond that which their SCBA can sustain their breathing air supply, resulting in a high probability of injury or death.
While there is currently an SCBA available that includes a full see-through augmented reality display, as disclosed in U.S. Pat. No. 7,110,013, the display is complicated, requiring special training on the part of the firefighter that will be using the display, and, due to the components included, expensive to procure. As such, there is an existing need for a directional indicator that is simple for the user to operate, inexpensive, and that may be attached to an existing face mask of a SCBA.
Likewise, there are currently separate compasses that may be carried externally by a firefighter or similar user, such as the Fireground Compass™ by Halcyon Products, Inc. However, such products must be carried externally, adding to the separate pieces of equipment that the firefighter must carry, which means that they are often left in the firefighter's truck. Additionally, since they are carried externally, there may be a delay as the firefighter locates the compass, brings it to a location that the firefighter can see it, and then reads the compass. Furthermore, in ‘zero-visibility’ environments, such a compass may be wholly unusable for its intended purpose. Furthermore yet, firefighters often wear thick gloves which can make obtaining and operating a hand-held compass cumbersome and unmanageable. As such, there is also an existing need for a directional indicator that may be attached to and integrated with an existing face mask of a SCBA.